“This important and fascinating book surely ranks among the most influential economic analysis of recent decades. Much of the debate over inequality in recent years is the result of the work of Thomas Piketty and his fellow researchers.­

Earlier research on inequality focused on data from household surveys described in terms of the “Gini” index, which measures the income distribution in a country. But the Gini misses much of the action at the top of the income distribution, partly because the very rich tend not to report all their income. And at best, these surveys measure income, not wealth.­

Piketty has painstakingly drawn on new data sources to show that income inequality has risen sharply in recent decades to extremely high levels in the United States and, to a lesser extent, in a handful of other English-speaking countries. The rise has been driven mostly by wage inequality between the top 1 percent of the wealthiest in society, and everyone else. (I wish there had been room in this long book to address the critics who attribute these results to distortions in the data.)”